Overview
EN ISO 385:2005 - Laboratory glassware - Burettes (ISO 385:2005) specifies metrological and construction requirements for an internationally acceptable series of glass burettes intended for general laboratory use. The standard aligns burette design with the principles of volumetric glassware in ISO 384, sets reference conditions (standard temperature 20 °C; 27 °C optional for tropical use), and defines how burettes are adjusted and verified for delivery volume.
Key topics and technical requirements
- Scope and adjustment
- Burettes are adjusted to deliver their stated volume (Ex) using water; delivery procedures and meniscus setting are defined.
- Reference temperature for calibration is 20 °C (27 °C where applicable).
- Classes and types
- Two accuracy grades: Class A (including Class AS, which requires a 30 s waiting time) and Class B.
- Two types by waiting time: no waiting time (A, B) and 30 s waiting time (AS).
- Maximum permissible errors
- Errors are specified by nominal capacity and subdivision. Table 1 in the standard covers capacities from 1 ml up to 100 ml and gives the allowed deviations and consistency across the scale.
- Materials and construction
- Glass must meet chemical resistance and thermal properties at least to HGB3 per ISO 719.
- Surface quality, absence of internal stress, and Schellbach tubing stripe limits are addressed.
- Stopcocks and delivery
- Stopcocks must permit smooth, precise control and meet leakage limits; designs may be glass or inert materials (ceramics, plastics).
- Requirements for delivery jet, delivery time, waiting time, and graduated scale positioning are specified.
- Dimensions and markings
- Scale lengths, overall lengths, zero-line positions and visibility of graduations/numbers are defined to ensure repeatable use and reading.
Applications and practical value
- Ensures consistent volumetric accuracy for common laboratory tasks such as titration, volumetric analysis, QA/QC testing, environmental and pharmaceutical assays, and educational laboratory work.
- Useful for manufacturers (design and production), calibration/verification laboratories, procurement/specification teams, and laboratory quality managers who need to comply with recognized metrological and construction standards.
- Improves traceability and comparability of volumetric measurements between labs and suppliers.
Who should use this standard
- Glassware manufacturers, laboratory equipment designers, calibration labs, ISO/CEN conformity assessors, laboratory managers in chemical, pharmaceutical, environmental and educational sectors.
Related standards
- ISO 384 - Principles of design and construction of volumetric glassware
- ISO 719 - Hydrolytic resistance of glass
- ISO 4787 - Methods for use and testing of volumetric glassware
- ISO 8655-3 - Piston burettes (for non-glass piston-type burettes)
Keywords: EN ISO 385:2005, burettes, laboratory glassware, volumetric instruments, Class A, Class B, Class AS, metrological requirements, ISO 384, calibration.